Overall meaning : Allah Almighty stresses that it is impossible for the devils to descend upon the Messenger, may Allah bless him and grant him peace: Shall I inform you of those upon whom the devils descend? They descend upon every excessive liar and excessive sinner (such as fortune-tellers). These devils stealthily eavesdrop on the high assembly of the angels in the heavens and then convey whatever they hear to their human allies, fortune-tellers, before the former are struck by shooting stars; and most fortune-tellers are liars. (They add one-hundred lies of their own to every word they hear from the devils before conveying that to people).
The Almighty then refutes the idolaters’ false claim that the Prophet, may Allah bless him and grant him peace, is a poet: Poets are followed by those who have gone astray and follow their own whims and desires. [By contrast, the Qur’an is not poetry, Muhammad is by no means a poet and his followers are rightly guided.]
Do you not see, Muhammad, that they speak falsehood in every genre of poetry they employ, roving about confusedly with whims and passions with no defined objective whatsoever, and that they say what they do not do? Not so the true believers among them, who do good deeds, remember Allah often, justly lampoon those who have unjustly satirised them to vindicate themselves and the Muslims. Such poets are by no means blameworthy.
Allah, Exalted be He, then concludes the surah in a threatening tone, saying: Those who have wronged themselves due to their unbelief and assaulting others will come to know the terrible consequences that they will suffer after their death.